Error (ORA-00923: FROM keyword not found where expected)

ora 923ORA-00923: FROM keyword not found where expected Below is the SQL : SELECT A.Agent_key, Sum(Total_Orders) FROM (SELECT A.Agent_key, Sum(Total_Orders)Learn the cause and how to resolve the ORA-00923 error message in Oracle. You tried to execute a SELECT statement, and you either missed or misplaced the FROM keyword.